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Advent of Bird Flu. Is it coming again?

Is bird flu coming again?

The house leaked in a rainy day, and the ship was late for a head start. The 2020 Gengzi Year of the Rat seems to have experienced the wrong way of opening, with mountain fires, locust plagues, plagues, and floods, all kinds of disasters coming one after another around the world.

At a time when the situation of the National New Coronavirus epidemic is severe, the familiar and unfamiliar term of bird flu has once again quietly landed on the land of China.
Avian Influenza Virus under electron microscope

On February 1, a poultry H5N1 subtype highly pathogenic avian influenza epidemic occurred in Shuangqing District, Shaoyang City, Hunan Province, where 7850 broilers were kept on the farm and 4,500 were sick.

On February 9, confirmed by the National Avian Influenza Reference Laboratory, H5N6 subtype highly pathogenic avian influenza occurred in poultry raised in a farm in Xichong County, Nanchong City, Sichuan Province, China.

What are the possible causes of these two different types of bird flu?


Avian influenza belongs to influenza A virus, and is divided into three levels: high, medium and low (non-pathogenic) according to the pathogenicity of the avian influenza virus. Due to the characteristics of the hemagglutinin structure of the avian influenza virus, this virus generally only infects birds.

H5N6 virus, H5N1 virus, etc. are all avian influenza viruses. They sound like different numbers. In fact, the difference between the numbers is the variation of virus traits:
  1. Various combinations of H1-H15, N1-N9
  2. Mainly found in various birds
  3. In rare cases, it can be transmitted to people. 
  4. The outer membrane of influenza virus particles is covered by two different types of surface glycoproteins, namely H (hemagglutinin) and N (neuraminidase). Among them, H has 15 subtypes and N has 9 subtypes. Therefore, the different subtypes of avian influenza are different in the arrangement and combination of these two surface glycoproteins.

Structure of Influenza Virus

Surface can find H (Hemagglutinin) and N (Neuraminidase)

However, the structure of the virus is simple, with natural genetic instability, and gene reassortment easily occurs during the replication process, resulting in structural changes. The subtypes can be said to be endless. 

Different combinations endow avian influenza viruses with different characteristics, and even gain the ability to spread across species. This is the cause of human infection with avian influenza.

Influenza virus invasion and replication

H5N6 is a subtype of avian influenza virus. The source of the virus is poultry, which is highly pathogenic to poultry. However, little news has been heard about the infection of this type of avian influenza in humans. For this reason, when the new H5N6 virus was first discovered in Laos in 2013, it did not attract people's attention.

It has always been a disease that only infected chickens and ducks. How can it spread to people?

Until May 2014, a 49-year-old male patient who had been exposed to dead poultry in Nanchong, Sichuan, was infected with the H5N6 avian influenza virus. He was clinically diagnosed with acute severe pneumonia and was rescued by the provincial and municipal joint expert team. 

This deceased person is the first case of human infection with the H5N6 subtype of avian influenza in the world, which means that this avian influenza virus can be infected by humans, and the current lethal rate is 100%. Since then, the H5N6 subtype avian influenza virus has been widely attention.

In 2017, a large area of ​​H5N6 avian influenza occurred in the Philippines

The H5N1 subtype avian influenza virus is even more notorious. The virus was first discovered in Hong Kong in 1997 and can directly infect humans. As of March 2013, a total of 622 people infected with highly pathogenic H5N1 avian influenza have been reported worldwide, of which 371 have died.

There are 45 cases found in our country, and 30 deaths. The mortality rate is extremely high, and most of them are young people and children, which is very harmful to society.

Now that the H5N1 subtype of avian influenza has reappeared in Hunan, it has not attracted much attention. This is entirely because the New Corona virus grabs the attention of the whole country. But considering the deadly H5N1 avian influenza virus, this virus should also be highly valued.

In fact, it has been widely spread in Asia, Africa, and Europe
Fortunately, there is no evidence of human-to-human transmission of the two avian influenza viruses present in China. It is enough to keep watching when it is necessary to take further measures to restrict human actions.

Avian influenza A H5N1 virus (gold)

But the gospel of man is not good news for poultry. The chickens, ducks, geese and the farmers behind them have suffered heavy losses this time.

For example, in the farms exposed to avian influenza in Xichong County, Sichuan Province, after the H5N6 subtype highly pathogenic avian influenza epidemic was discovered, according to the report of the Chinese Center for Animal Disease Control and Prevention, 2,497 poultry were listed and 1,840 were sick. 

In order to avoid the spread of the virus and the entry of sick and dead poultry into the market, the local area killed 2261 poultry in accordance with the relevant preplans and prevention and control technical specifications. All the sick and dead poultry have been harmlessly treated.

Not only poultry, but wild birds can also be infected with the bird flu virus. And because many wild birds have migratory characteristics, they may carry the avian influenza virus and spread to a larger space-time range.

Birds dying from bird flu

Compared to the concentration of breeding plants, wild birds are more uncontrollable.
On January 21, the Ministry of Agriculture and Rural Affairs received a report from the Chinese Center for Animal Disease Control and Prevention. After being diagnosed by the National Avian Influenza Reference Laboratory, the H5N6 subtype highly pathogenic avian influenza epidemic occurred in wild swans in the Daquangou Reservoir in Shihezi City. 
There are more than 150 swans in the area, 19 of which are sick and all died.

The waters of Daquangou belong to hot spring water. The warmth in winter attracts many different types of waterbirds to spend the winter. Wild birds like the Daquangou swan are one of the most unstable factors for the spread of bird flu.

Off grain

This outbreak of avian flu seems to be accidental and actually has its inevitability, so we have to mention the new coronavirus epidemic we are experiencing.

Originally, winter and spring were the periods of high incidence of influenza. Most of the patients admitted to human hospitals were influenza patients, and poultry was no exception. Viruses that are highly sensitive to temperature, ultraviolet rays, etc., are the most active time for this season, which is the basis for the emergence of avian influenza. There were winter and spring, unexplained poultry deaths in the breeding plant

Farmers should pay attention to it

Under the influence of the new crown epidemic this year, national logistics have been affected, and the poultry farming industry has also been affected. There is currently no evidence that the new coronary pneumonia epidemic is related to poultry, but the live poultry trading market in many places has been closed.

As the new coronary pneumonia epidemic continues, many places across the country have proposed to initiate a first-level response to major public health emergencies. In order to effectively prevent the spread of pneumonia epidemics, many places including Henan, Hubei and Yunnan issued a document requesting a total ban on the sale of live poultry in the market.

In fact, prior to this, many places including Beijing, Shanghai, Zhejiang, etc. n China have required different levels of restrictions on live poultry trading. This is currently the main poultry transaction method.

In the township market, live poultry is more popular than processed frozen meat.
Similar phenomena have been staged in many places across the country. In this way, most of the meat, chicken and ducks that should have flowed into the market are backlogged in various farms. Farmers scattered all over the country are suffering, but they have no other choice but to wait anxiously for the new coronary pneumonia epidemic to improve. Even chickens that can lay eggs have a hard time

The price of eggs is not pleasant

In this process, the number of chickens and ducks and other poultry in the poultry farms gradually increased, and the pressure to clean, ventilate, and eliminate sick and dead poultry increased, and manufacturers did not invest more power to create soil for the development and spread of poultry diseases.

The average chicken area is getting smaller and smaller.
And under the influence of the new coronavirus epidemic, not only can birds not be transported out, but feed cannot be transported in. Previously, the main feed sources for the provinces in the Yangtze River Basin were mostly corn and soybean meal transported by water from the Northeast and coastal areas.

Affected by road closures in various places, a large amount of feed cannot be transported into the farm, and all are transported by small trucks.

Due to the poor transportation of feed materials, farming enterprises in various regions have been subjected to varying degrees of grain cuts.

Once the feed intake of chickens and ducks is insufficient, it is difficult to replenish their physical strength, and their immunity declines, which will greatly increase the probability of bird flu.


Grain cut + high load operation makes the risk of avian influenza infection an accidental necessity.

Dangerous live birds

Will avian influenza become another health risk after the new coronavirus?

From the current information, it is not worth panic but it has to be guarded against.

Avian flu outbreaks of varying degrees occur in China every year, and relevant health departments and large-scale farms have already made plans. Only this year's situation is special, because of the impact of the new coronavirus, the response to the outbreak of avian influenza has weakened accordingly.

Poultry flu vaccines are difficult to get 100%

After all, they do not have an account, it is difficult to control the number

Bird flu is generally not transmitted to people. However, with the changes in the global ecological environment, avian influenza, which was originally prevalent in wild poultry, frequently spread in poultry.

The frequent contact between humans and poultry has also made it possible for the avian influenza virus to mutate in the human body, constantly adapting in both directions, and ultimately causing human disease.

Studies have also shown that direct contact with poultry or wild birds is an important means of transmission of H5N6 subtype avian influenza virus. Therefore, people engaged in live poultry breeding, processing, trading, or frequent entry and exit of the live poultry market are high-risk groups.

Farms and live poultry markets where people and poultry live together provide convenient conditions for the rearrangement of viral genes, the evolution and spread of viruses, and are the main places for the spread of viruses.

Studies have shown that most cases of H5N6 subtype avian influenza have a history of exposure to the live poultry market before the onset of the disease, especially for elderly people with underlying diseases and low immunity.

People in the industry are in close contact with poultry. If bird flu occurs, they are often the first to suffer

At present, there is no definite evidence of human-to-human transmission of H5N6 subtype avian influenza and H5N1 subtype avian influenza, but it is not to say that it is safe to stay away from poultry. Rural poultry and other livestock are also hidden.

Some researchers have isolated H5N6 subtype avian influenza virus in domestic cats, pigs and other animals, and the viral gene sequence isolated in domestic cats has high homology with human infected strains, indicating that the virus is likely to infect and adapt Cats and other mammals are then transmitted to humans through direct contact, so it is also a potential threat to humans.
President Ford vaccination against swine flu

A small number of patients, especially older patients who are not treated in time, will rapidly develop progressive pneumonia and acute respiratory distress syndrome. If not treated in time, it will lead to death, which is no less harmful than neopneumonia.

It is worth noting that in addition to the two subtypes of avian influenza currently appearing in China, the World Organization for Animal Health (OIE) recently announced that a highly contagious H5N8 subtype of avian influenza has also erupted in Saudi Arabia.

 The outbreak occurred in the Suder region of central Saudi Arabia, approximately 150 kilometers north of the capital Riyadh. This bird flu has killed more than 22,000 birds. For safety reasons, more than 385,000 birds were ordered to be culled.

Usually a large area of ​​foam causes the birds to suffocate.

Earlier on January 18, Vietnam issued a similar bird flu outbreak alert. Another highly pathogenic virus strain H5N6 that occurred in a village in the north of the country killed 2,200 birds.

It seems that chickens, ducks, geese all over the world have not passed this year.

Author's Bio

Doctor Shawna Reason, Virologist
Dr. Shawna Reason
Name: Shawna Reason

Education: MBBS, MD

Occupation: Medical Doctor / Virologist 

Specialization: Medical Science, Micro Biology / Virology, Natural Treatment

Experience: 15 Years as a Medical Practitioner

About Me

Quora Profile


"Saudi Arabia Report: H5N8 Highly Pathogenic Avian Influenza Outbreak" Wu Jinming

"H5N6 Avian Influenza Research Status and Thinking of Prevention and Control" Xiong Jie Zhang Xintong

Press Office of the Ministry of Agriculture and Rural Affairs

"Poultry Industry under the New Crown Epidemic" Jiang Zheng, "China Business News"

* The content of this article is a generic opinion and does not represent the position of the Earth Knowledge Bureau

Author's Bio

Doctor Shawna Reason, Virologist
Dr. Shawna Reason
Name: Shawna Reason

Education: MBBS, MD

Occupation: Medical Doctor / Virologist 

Specialization: Medical Science, Micro Biology / Virology, Natural Treatment

Experience: 15 Years as a Medical Practitioner

About Me | Linkedin | Quora Profile | Medium Profile | Twitter



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